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Title: Some aspects of the relation between Pi 1-2 magnetic pulsations observed at L - 1. 3-2. 1 on the ground and substorm-associated magnetic field variations in the near-earth magnetotail observed by AMPTE CCE

Abstract

The relation between Pi 1-2 pulsations on the ground and substorm-associated magnetic field variations in space has been studied using data obtained on the ground at low-latitude conjugate stations (L = 1.3-2.1) and in the near-Earth magnetotail by the AMPTE CCE spacecraft. The ground-based data were acquired in a campaign period from July 20 to September 16, of 1986, during which the apogee of CCE (8.8 R{sub E}) was located between 2330 and 0230 hours magnetic local time. Of 16 clear magnetic field dipolarizations observed at CCE, all had a corresponding Pi 2 pulsation on the ground, with a time lag of +1 to {minus}7 min. For most (13) of these cases, the time lag was equal to or shorter than 2 min. However, the authors also found Pi 2 pulsations that do not accompany a dipolarization at CCE. These results are consistent with previous observations, which showed that Pi 2 pulsations are a global indicator of the expansion phase onset of a substorm, whereas dipolarizations occur in a limited region in the near-Earth magnetotail. One of the 16 events, which occurred on August 28, 1986, is studied in detail because a 13-s Pi 1 pulsation was observed on themore » ground in addition to an ordinary Pi 2 pulsation. For this event, CCE also observed a {approximately} 13-s oscillation at {approximately} 8.1 R{sub E} in the midplane of the magnetorail near midnight (Takahashi et a., 1987). They suggest that field line resonance driven by a quasi-monochromatic oscillation in the near-Earth tail is the cause of the Pi 1 pulsation observed on the ground. The commonly observed Pi 2 pulsations could be attributed to other wave excitation mechanisms including transient response of the magnetospheric cavity to a substorm-associated impulse.« less

Authors:
;  [1]; ; ;  [2]; ;  [3]
  1. Tohoku Univ., Sendai (Japan)
  2. Johns Hopkins Univ., Laurel, MD (USA)
  3. Univ. of Newcastle, New South Wales (Australia)
Publication Date:
OSTI Identifier:
6049602
Resource Type:
Journal Article
Journal Name:
Journal of Geophysical Research; (USA)
Additional Journal Information:
Journal Volume: 94:A4; Journal ID: ISSN 0148-0227
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; GEOMAGNETIC FIELD; PULSATIONS; MAGNETIC BAYS; COMPARATIVE EVALUATIONS; EARTH MAGNETOSPHERE; EXPANSION; HYDROMAGNETIC WAVES; IONOSPHERE; MAGNETOTAIL; SATELLITES; VARIATIONS; WAVE FORMS; EARTH ATMOSPHERE; MAGNETIC FIELDS; PLANETARY IONOSPHERES; 640201* - Atmospheric Physics- Auroral, Ionospheric, & Magetospheric Phenomena

Citation Formats

Yumoto, K, Saito, T, Takahashi, K, Potemra, T A, Zanetti, L J, Menk, F W, and Fraser, B J. Some aspects of the relation between Pi 1-2 magnetic pulsations observed at L - 1. 3-2. 1 on the ground and substorm-associated magnetic field variations in the near-earth magnetotail observed by AMPTE CCE. United States: N. p., 1989. Web. doi:10.1029/JA094iA04p03611.
Yumoto, K, Saito, T, Takahashi, K, Potemra, T A, Zanetti, L J, Menk, F W, & Fraser, B J. Some aspects of the relation between Pi 1-2 magnetic pulsations observed at L - 1. 3-2. 1 on the ground and substorm-associated magnetic field variations in the near-earth magnetotail observed by AMPTE CCE. United States. https://doi.org/10.1029/JA094iA04p03611
Yumoto, K, Saito, T, Takahashi, K, Potemra, T A, Zanetti, L J, Menk, F W, and Fraser, B J. 1989. "Some aspects of the relation between Pi 1-2 magnetic pulsations observed at L - 1. 3-2. 1 on the ground and substorm-associated magnetic field variations in the near-earth magnetotail observed by AMPTE CCE". United States. https://doi.org/10.1029/JA094iA04p03611.
@article{osti_6049602,
title = {Some aspects of the relation between Pi 1-2 magnetic pulsations observed at L - 1. 3-2. 1 on the ground and substorm-associated magnetic field variations in the near-earth magnetotail observed by AMPTE CCE},
author = {Yumoto, K and Saito, T and Takahashi, K and Potemra, T A and Zanetti, L J and Menk, F W and Fraser, B J},
abstractNote = {The relation between Pi 1-2 pulsations on the ground and substorm-associated magnetic field variations in space has been studied using data obtained on the ground at low-latitude conjugate stations (L = 1.3-2.1) and in the near-Earth magnetotail by the AMPTE CCE spacecraft. The ground-based data were acquired in a campaign period from July 20 to September 16, of 1986, during which the apogee of CCE (8.8 R{sub E}) was located between 2330 and 0230 hours magnetic local time. Of 16 clear magnetic field dipolarizations observed at CCE, all had a corresponding Pi 2 pulsation on the ground, with a time lag of +1 to {minus}7 min. For most (13) of these cases, the time lag was equal to or shorter than 2 min. However, the authors also found Pi 2 pulsations that do not accompany a dipolarization at CCE. These results are consistent with previous observations, which showed that Pi 2 pulsations are a global indicator of the expansion phase onset of a substorm, whereas dipolarizations occur in a limited region in the near-Earth magnetotail. One of the 16 events, which occurred on August 28, 1986, is studied in detail because a 13-s Pi 1 pulsation was observed on the ground in addition to an ordinary Pi 2 pulsation. For this event, CCE also observed a {approximately} 13-s oscillation at {approximately} 8.1 R{sub E} in the midplane of the magnetorail near midnight (Takahashi et a., 1987). They suggest that field line resonance driven by a quasi-monochromatic oscillation in the near-Earth tail is the cause of the Pi 1 pulsation observed on the ground. The commonly observed Pi 2 pulsations could be attributed to other wave excitation mechanisms including transient response of the magnetospheric cavity to a substorm-associated impulse.},
doi = {10.1029/JA094iA04p03611},
url = {https://www.osti.gov/biblio/6049602}, journal = {Journal of Geophysical Research; (USA)},
issn = {0148-0227},
number = ,
volume = 94:A4,
place = {United States},
year = {Sat Apr 01 00:00:00 EST 1989},
month = {Sat Apr 01 00:00:00 EST 1989}
}